Nut-tapping machine.



Wtin'esses No. 862,281. I PA-TENTED AUG. a, 1907. J. M. RALSTON.-

NUT TAPPING MACHINE. APPLICATION I'ILED 1130.19, 1905.-

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No. 862,281. PATENTED AUG. 6, 1907. J. M. RALSTON.

NUT TAPPING MACHINE.

APPLICATION FILED DEO.19,1905( I '2 BHEETSSHEET 2.

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UNITED STATES PATENT or ruon.

JOHN MILLER RALSTON, OF BARRHEAD, SCOTLAND, ASSIGNOR TO JAMES HARPER MATHIESON AND THOMAS OGILVIE MATHIESON, OF GLASGOW, SCOTLAND.

NUT-TAPPING MACHINE.

To all whom it may concern:

Be it known that I, JOHN MILLER RALSTON, a subject of the King of Great Britain and Ireland, residing in Barrhead, Scotland, have invented certain new and useful Improvements in and Relating to Nut-Tapping Machines, of which the following is a specification.

This invention relates to improvements in and relating to nut tapping machines and refers more particularly to the machine described and illustrated in the specification and drawings forming part of the application for Letters Patent No. 271150 filed 25th July 1905, and which on May 22nd, 1906 matured into Letters Patent No. 821,376, in which is described mechanism for holding the tap comprising two sets of alternately acting horizontally disposed grips, and a vertical plunger or forcer for holding the nut during the tapping operation. I

The present invention has for its object to provide means whereby the removal or replacement of the tap may be easily and readily effected and further to permit the employment of various sizes of taps for tapping various sized nuts.

In carrying the invention into effect instead of forming the plunger or forcer in one piece as in the machine above referred to, the said plunger is in two parts one of which is pivotally secured to the other, the movable portion being the lower, to which is pivotally connected a socket for retaining the nut during the tapping operation. By this means when it is desired to remove the tap the said forcer may be lifted bodily and the lower'portion swung out of the way to permit ready access to the tap so that its removal or replacement can be expeditiously and easily accomplished. Further, instead of forming the nut socket at the end of the plunger in one with the same, I employ a socket formed separately from the plunger and so constructed as to enable it to be readily secured to or removed from the said plunger.

As will be readily understood the shank attached to the tap, which shank is held by the grips during the tapping operation, will vary in diameter in accordance with the size of the tap itself, the variation in size being necessary upon the one hand in order to enable the shank to stand the torsional strain imposed upon it during the tapping of the nut, and on the other hand the diameter of the shank must be sufficiently small to enable the nuts when tapped to pass readily thereover. Under these circumstances, it is requisite that means be provided whereby the limit of inward movement of the grips may be varied to accommodate the size of the tap in use. In order that this may be effected without interfering with the operating mechanisin for the grips, instead of mounting the locking bars for the upper grips upon a plain pin as in the ma- Specification of Letters Patent.

Patented Aug. 6, 1907.

Application filed December 19 1905- Serial No. 292,439.

chine before referred to, I substitute therefor a pin.

having that portionof its body supporting the locking bar eccentric to the main portion. Means are provided whereby the pin may be rotated in its supports and after adjustment locked in position. By this means the locking bars may be advanced or withdrawn in the horizontal plane in order to lock thegrips when they are in contact with the squares on the shank of the tap. The lower grips are under the influence of a spiral or other spring with free end acting upon the outer side or edge of the grips 3 In order that the invention may be the better und erstood, drawings are appended in which:

Figure 1 is a longitudinal section of a part of a machine embodying the present invention. Fig. 2 is also a longitudinal section but taken at right angles to Fig.

1. Fig. 3 is an enlarged sectional plan showing the method of attaching the nut socket to the end of the plunger or forcer. Fig. 3 shows the socket in course of connection with the forcer. Fig. 4 is an enlarged sectional detail of the means for effecting the adjustment of the locking bars for the grips, and Fig. 5 is a sectional plan on line A A Fig. 2. I

Referring to the drawings, 3, 3, indicate respectively the upper and lower grips for the tap 4. The general arrangement of the grips is as in the previous machine before referred to, the movement of the said grips being effected as in the previous instance by means of the segments 5, which alternately cause the grips to close upon and retain the tap 4. The locking bars q q for engaging the upper grips and holding them positively in the engaged position are mounted upon pins g (1 provided at g with an eccentric portion carrying the end of the bar q aforesaid. Coiled round the eccentric portion g of the pins is a spiral spring q with its free end pressing on the lower side of bar g said spring bringing bar (1 into position for locking grips 3, the bar being also held fast against accidental movement by the bottom of the slot q in the sliding plate q carrying the racks for operating the segments 5. The operation of the locking bars is substantially the same as in the prior patent before referred to, the disengagement of the said bars being effected by the upper edge of the slot g in plate q coming into contact with the locking bar pushing it down against the action of spring q. The body of the pin is mounted in lugs q q between which the pin is clamped by means of the nut (1 To facilitate the rotation of the pins one end is squared so that by means of a spanner or other instrument they may be rotated to adjust the position of the locking bars and held against rotation during the tightening of the nut (1 By this means the locking bars may be advanced or withdrawn in the horizontal plane in accordance with the limit of inward movement of the grips determinable by the size of the shank of the tap. In order to allow as wide a range of movement as possible there may be employed for the lower grips a spiral spring 4 coiled round pin 6 with its free end pressing on the outer edge or side of grips 3.

In order to permit ready access to the tap or for the purpose of changing the socket carrying the nut, I form the forcer 24 in two parts of which the lower 24 is pivotaliy secured to the upper by means of studs or screws 24 and to the ends of which studs is connected the lever 27 or raising the plunger against the action of the spring 25. The spring depresses the plunger and forces nut on to the tap. When it is desired to remove the socket or holder or to inspect or remove the tap, the lever 27 to which is attached the i'orcer 24 is raised bodily until its lower end is clear of the guide ring .9. This being accomplish ed, the lower portion 24, may be hinged upon its pivots leaving the tap exposed and permitting ready access thereto.

The nut holder or socket 24 just above referred to is formed separate from the lower end of the forcer 24! this being necessary in order that the socket may be changed for other sockets in accordance with the size of nut being tapped. To facilitate its ready removal or attachment, I provide the lower end of the forcer with horizontal projections 24 Figs. 3 and 3' of circular outline. The nut socket is provided upon its upper surface with projections 24 which are recessed upon their inner faces to receive the projections 2 upon the end oi the forcer. The parts are connected by in troducing the lower end of the iorcer between the pro jections 24, Fig. 5 shows this operation being effected,

and when the said projections 24 are in alinement with the recesses in the projections 24 a partial rotation of the socket will bring the parts into engagement to prevent the rotation of the holder. 7 I

To prevent the rotation of the holder d uring the tapping of the nut, channel's 25ware formed upon the circumierence of the said holder, which channels engage the vertical. ribs or projections 26 formed upon the interior of the guide ring .9. By this means the friction necessary to be overcome when forcing the nut downward is reduced to a minimum. It is evident that by means tap be readily attained when desired, but the capacity oi the machine is considerably increased as the one machine may be employed for tapping various sizes of nuts.

it will be understood that it is necessary to vary the speed of rotation of the tap in accordance with the size thereof and this would be effected byyarying the proportions of the driving and driven bevel wheels by which the rotation of the'tap is effected.

Having now particularly described and ascertained the nature of my said invention and in what manner the same is to be performed, I declare that what I claim is I 1. In a nut tapping machine the combination with horizontally reciprocating grips for holding the taps during the tapping operation, of pins provided with a portion disposed eccentrically with regard to the body of said pin, locking bars pivotally supported thereon, means for rotating said pins to effect the longitudinal adjustment of the locking bars, and means for securing the pin after adjustment.

2. In a nut tapping machine, the combination with means for supporting and rotating a tap, of a plunger for forcing nuts on to said tap, means for guiding said plunger in a path parallel with the axis of rotation of the tap, said plunger comprising two members pivoted together, means for reciprocating the plunger in said path, a nut holder having a circular opening for receiving the end of the plunger and a passageway of less width than the diameter of the opening communicating with the same, said plunger having a circular portion for fitting the opening in said holder and being flattened for traversing said passageway.

3. In a nut tapping machine, the combination With means for supporting and rotating a tap, of a plunger for forcing nuts on to said tap, a nut holder having a circular opening for receiving the end of the plunger and a passageway of less width than the diameter of the opening communicating with the same, said plunger havinga cir cular portion for fitting the opening in said holder and being flattened for traversing said passageway.

In witness whereof I have hereunto set my hand in the presence of the two undermentioned witnesses.

.IOIIN MILLER RALSTON.

Witnesses .ToIiN Roy, ALEXANDER CAMERON. 

